WASHINGTON — On Thursday night, hundreds of American Jewish leaders visited the White House to celebrate Hanukkah, but many also came with a less celebratory agenda: They were there to deliver a warning to President Barack Obama about the potential nomination of former Sen. Chuck Hagel.

The buzz around the former Republican senator from Nebraska — seen as a top contender to lead the Department of Defense — has Israel supporters worried. Hagel has been a frequent target for Jewish Democratic and Republican groups for more than a decade, even as he is close to Obama, having been a supporter in 2008 and an appointee to the President’s Intelligence Advisory Board.

“He was one of these worst senators in his party in memory when it comes to Israel,” said one Jewish Democratic operative. “It’s a terrible idea.”

Hagel is hardly overtly anti-Israel, but he's been less sympathetic to the Jewish State than most members of Congress in both parties. He was a critic, for instance, of Israel's assault on the Lebanese group Hezbollah in 2006, and his broader worldview — he's a "Republican realist," the political scientist and archenemy of what he calls the "Israel lobby" Stephen Walt wrote Thursday — is unsympathetic to an emotional American engagement in the Middle East.

And with Susan Rice withdrawing her name from contention to be secretary of state, Republicans are gearing up for fight against Hagel, despite his fading ties to their party.

“Republicans will now turn their attention to blocking a potential Hagel nomination,” said one Senate GOP foreign policy aide, “which could become an ideological litmus test on foreign policy for both Republicans and Democrats.”

Complicating the potential selection of Hagel by Obama is that Jewish Democrats, including one of the men to whom Obama would likely turn to assuage the fears of Jewish Americans, is on record raising doubts about him.

"If [Hagel] was taking a policy role, we'd have real concerns," Ira Forman, the Obama campaign’s Jewish Outreach Director and the former executive director of the National Jewish Democratic Council, told The Weekly Standard when Hagel was appointed to the intelligence board.

In 2007, when Hagel flirted with a presidential run, the NJDC blasted his credentials on Israel in a fact sheet, noting, among other items, that in 2006, Hagel was “one of only 12 Senators who refused to write the EU asking them to declare Hezbollah a terrorist organization.”

Several attendees at the Hanukkah party said they witnessed or participated in reaching out to administration officials about the potential selection of Hagel, with one attendee saying “he was the talk of the party.”

One Democrat in attendance predicted the fight over Hagel would be “Susan Rice times 10.”

On Thursday, White House Press Secretary Jay Carney declined to comment on what Israel supporters would think of a Hagel pick.

“The president thinks very highly of Senator Hagel,” Carney told reporters. “I think a lot of people in Washington and around the country, and especially in Senator Hagel’s home state, think very highly of him.”